Monday, 21 June 2010

I went to my local lumber merchant on Friday and ordered the lumber for my boat. It's getting delivered, so hopefully it will be here tomorrow (Tuesday).In preparation to mill my own strips I decided to spend money on a new saw blade which has a thin kerf. (Kerf: a groove or slit in material caused by cutting) This would waste 2mm per cut, instead of 3mm. Since each strip would be 6mm thick, this means an extra strip per each six cut strips. Nice!

Planks from which strips will be cut are generally 150mm-200mm wide, they are around 25mm thick and vary in length from 3m to 4.8m. The strips need to be approx. 19mm wide, 6mm thick, by the length of the plank (preferably 6m - but this is not available).This picture gives you an idea of how the strips are milled from a plank.

This milling operation has been really stressing me. It's a huge task to accomplish alone, when you are lacking a lot of tools to help ease the job.

A 3m long plank must be fed into the table saw, keeping the plank tight against the fence, maintaining a steady speed, and the same plank must be caught at the outfeed side, together with the strip which has been cut.Space is my primary concern, but the amount of noise I would generate would be a second and valid concern too.

When I got to the lumber merchant, the man helping me, milled some sample strips. I was dumbstruck, since the lady on the phone told me that it was impossible for them to mill the strips.Anyways, after seeing this, I went straight to the lady and requested that the wood I order be milled into 6mm strips. Since I showed her the sample strips, she happily agreed. Wow. How nice is this? I'll be getting my strips delivered (together with a few planks which I need to custom cut) with no further work required.I walked out of there with a huge smile on my face.

Oh, and least I forget, the wood I ordered was Obeche for the main body of the boat and African Mahogany for the accent strips, for the keel, king plate, gunwales, seats, etc.I am fairly certain that there will be no problems with the mahogany. As far as the Obeche is concerned, I am hoping for the best since I have no idea if this will be acceptable. Personally I see no reason why this wood is not going to work just fine for the task I have in mind for it.I spent a good part of three months looking for help regarding which wood I could substitute for Western Red Cedar, which is the designer recommendation. Obviously I need a substitute which is readily available in South Africa. The only cedar I found here, are short planks of 2.4 meter length and horrendously full of knots. It is my layman's opinion that every single strip will crack at a knot, somewhere along it's short length.Looking for advice has been an absolute dead-end.I have written to numerous people and requested advice. Of all the people I wrote to, I received two one-line replies and the rest never bothered to answer. I wrote to a boat designer, a naval architect, an expert woodcrafter who claims to have learnt his craft in the boating industry, a few lumber mills, a specialist in lumber procurement and a company specialising in supplying the marine industry, amongst others. I also posted in forums, one specialising in wooden boats and never got any advice from there either.

So, at the end of the day I am left to my own devices, having to make choices based on my limited knowledge. Hopefully I can come up with the right combination of choices, build my boat, and end up being able to pass along the advice to the next guy looking...

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comments:

Couple of things:Keeping the lumber straight - You need a free standing roller to hold the wood. .. and against the fence - You need a feather board (which can be fixed to the table saw somehow)Cutting: How much wastage is there at the lumber supplier? i.e. the kerf? (Even if 3mm, still worth it for the hassle saved). Are they going to be accurate?

The kerf at the lumber supplier is 3mm. Yes, it is still worth it.The accuracy was stressed to the man who will do the cutting. I am still waiting for the results.

Featherboards and free standing roller/s are most definitely going to be needed. Even so it will still be a tough job to do single-handed and ensure accurate cuts. I'll cross that bridge when I get to it.